1. Field of the Invention
This invention relates to an epoxy resin composition having a low melt viscosity enough to mold on a thin multi-pin semiconductor device without causing damages thereto and a semiconductor device encapsulated with a cured product of the composition.
2. Prior Art
For epoxy resin compositions serving as an encapsulant for modern thin packages, the current approach taken in order to find a compromise between filling improvement and low water absorption is to blend a large proportion of a submicron filler having a mean particle size of less than 1 .mu.m, desirably less than 0.5 .mu.m. Since such a submicron filler has an extremely greater specific surface area than conventional fillers, the interfacial wetting between the filler and the resin is significantly exacerbated. As a result, the composition has an extremely high viscosity and becomes difficult to mold.
Another recent approach is to increase the loading of a filler to reduce water absorption for the purpose of improving reflow soldering resistance. Particularly when the loading is more than 85% by weight, spherical fillers conventionally used can cause die pad deformation and wire deformation and even line failures because the viscosity of loaded resin in the low shear region becomes very high.